Environmental Factors Affecting Methoprene Concentrations for West Nile Virus Control in a Storm Sewer System

2009 ◽  
Vol 44 (2) ◽  
pp. 141-150 ◽  
Author(s):  
James Y. Li ◽  
Ching Lo ◽  
Peter D. Luciani ◽  
Angelune Des Lauriers ◽  
Kevin Sze ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Sewer System ◽  
West Nile ◽  
Rainfall Events ◽  
Factors Affecting ◽  
Daily Monitoring ◽  
Vector Borne ◽  
Water Volumes ◽  
Number Of Cycles ◽  
Storm Sewer

Abstract To address vector-borne West Nile virus in Canada, chemical larvicides (methoprene) are applied to storm sewer system catch basins (CBs) to control mosquitoes. This study assessed the fate and transport of methoprene in such systems over time relative to precipitation. Rainfall and methoprene concentration patterns revealed the effect of dilution, dissolution, and flushing of the larvicide. In the summer and fall of 2003 to 2005, field monitoring studies were conducted in Toronto, Ontario on two CBs, each treated with a control dose of methoprene, supplied in pellet or ingot formulation. Furthermore, in 2005, concentrations at the storm sewer outfall were measured during nine rainfall events. Based on daily monitoring, findings indicate that (1) the methoprene concentration at the CBs fell below the minimum lethal concentration or LC50 one or two weeks after treatment, and remained below LC50 concentrations over 70% of the time; (2) rainfall flushed methoprene from the CBs to the storm sewer outfall at concentrations higher than the levels specified by Ministry of Environment, which may cause ecosystem damage; (3) based on the number of cycles per diem within each CB in each study period, there was no conclusive pattern in the flushing susceptibility of pellets versus ingots; (4) the mean concentration of methoprene increased with reduced CB sump volume; (5) less total precipitation resulted in higher average methoprene concentrations and a higher number of days above the LC50 based on ingot-dosed CBs; (6) counter-intuitive to (4) and (5), larger sump water volumes and greater rainfall resulted in lower mean concentrations and fewer days above the LC50; and (7) a single ingot dosage was comparable in performance to a three pellet dosage.

Monitoring the fate of methoprene larvicide for West Nile virus management

2006 ◽  
Vol 54 (11-12) ◽  
pp. 395-402
Author(s):  
J. Li
Keyword(s):  
New York ◽  
West Nile Virus ◽  
Mosquito Control ◽  
Gas Chromatography Mass Spectrometry ◽  
West Nile ◽  
Rainfall Events ◽  
Catch Basin ◽  
Vector Borne ◽  
Catch Basins ◽  
The City

Since the outbreak of vector-borne West Nile virus in New York City in 1999, the disease has spread across United States and Canada, resulting in the use of larvicides such as methoprene at catch basins for widespread urban mosquito control. Although the manufacturer has recommended a methoprene dosage for catch basin application, the effect of rainfall on this dosage is not known. A field study on the fate of methoprene pellets and ingots was conducted during the summer of 2004 at three catch basins in the City of Toronto, Canada. Water samples from each catch basin were collected daily and during rain storms and analyzed for methoprene concentration using gas chromatography mass spectrometry. It was found that: (1) the methoprene concentration at the catch basin sump fell below the minimum lethal concentration most of the time; (2) rainfall events greater than 25 mm flushed methoprene pellets out of the catch basin; (3) the higher the sump water depth, the higher the residual methoprene concentration at the catch basin sump; and (4) rainfall flushed methoprene from the catch basins into the storm sewer outfall at concentrations much lower than the detrimental level which might cause ecosystem damage.

scholarly journals Predicted and observed mortality from vector-borne disease in wildlife: West Nile virus and small songbirds

2013 ◽  
Vol 165 ◽  
pp. 79-85 ◽  
Author(s):  
A. Marm Kilpatrick ◽  
Ryan J. Peters ◽  
Alan P. Dupuis ◽  
Matthew J. Jones ◽  
Peter Daszak ◽  
...  
Keyword(s):  
West Nile Virus ◽  
West Nile ◽  
Vector Borne Disease ◽  
Vector Borne

Effects of climate change on vector-borne diseases: an updated focus on West Nile virus in humans

2019 ◽  
Vol 3 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Shlomit Paz
Keyword(s):  
Climate Change ◽  
West Nile Virus ◽  
The West ◽  
West Nile ◽  
Local Conditions ◽  
Transmission Season ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
The Impact ◽  
Impacts Of Climate Change

Abstract One of the main impacts of climate change on health is the influence on vector-borne diseases (VBDs). During the last few years, yearly outbreaks of the West Nile virus (WNV) have occurred in many locations, providing evidence of ongoing transmission. Currently, it is the most widely distributed arbovirus in the world. Increases in ambient temperature have impacts on WNV transmission. Indeed, clear associations were found between warm conditions and WNV outbreaks in various areas. The impact of changes in rainfall patterns on the incidence of the disease is influenced by the amount of precipitation (increased rainfall, floods or droughts), depending on the local conditions and the differences in the ecology and sensitivity of the species of mosquito. Predictions indicate that for WNV, increased warming will result in latitudinal and altitudinal expansions of regions climatically suitable for transmission, particularly along the current edges of its transmission areas. Extension of the transmission season is also predicted. As models show that the current climate change trends are expected to continue, it is important to reinforce WNV control efforts and increase the resilience of population health. For a better preparedness, any assessment of future transmission of WNV should consider the impacts of the changing climate.

scholarly journals Persistent impacts of West Nile virus on North American bird populations

2015 ◽  
Vol 112 (46) ◽  
pp. 14290-14294 ◽  
Author(s):  
T. Luke George ◽  
Ryan J. Harrigan ◽  
Joseph A. LaManna ◽  
David F. DeSante ◽  
James F. Saracco ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Disease Risk ◽  
Phylogenetic Analyses ◽  
West Nile ◽  
Factors Affecting ◽  
Bird Populations ◽  
Continental Scale ◽  
North American Bird ◽  
Avian Populations ◽  
The Impact

Since its introduction to North America in 1999, West Nile virus (WNV) has had devastating impacts on native host populations, but to date these impacts have been difficult to measure. Using a continental-scale dataset comprised of a quarter-million birds captured over nearly two decades and a recently developed model of WNV risk, we estimated the impact of this emergent disease on the survival of avian populations. We find that populations were negatively affected by WNV in 23 of the 49 species studied (47%). We distinguished two groups of species: those for which WNV negatively impacted survival only during initial spread of the disease (n = 11), and those that show no signs of recovery since disease introduction (n = 12). Results provide a novel example of the taxonomic breadth and persistent impacts of this wildlife disease on a continental scale. Phylogenetic analyses further identify groups (New World sparrows, finches, and vireos) disproportionally affected by temporary or persistent WNV effects, suggesting an evolutionary dimension of disease risk. Identifying the factors affecting the persistence of a disease across host species is critical to mitigating its effects, particularly in a world marked by rapid anthropogenic change.

scholarly journals Identification of Climatic Factors Affecting the Epidemiology of Human West Nile Virus Infections in Northern Greece

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0161510 ◽  
Author(s):  
Nikolaos I. Stilianakis ◽  
Vasileios Syrris ◽  
Thomas Petroliagkis ◽  
Peeter Pärt ◽  
Sandra Gewehr ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Climatic Factors ◽  
Virus Infections ◽  
Northern Greece ◽  
West Nile ◽  
Factors Affecting ◽  
Human West Nile Virus

scholarly journals Serological Evidence of West Nile Virus in Wild Birds in Bangladesh

2020 ◽  
Vol 7 (4) ◽  
pp. 164
Author(s):  
Ariful Islam ◽  
Shariful Islam ◽  
Mohammad Enayet Hossain ◽  
Jinnat Ferdous ◽  
Josefina Abedin ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Migratory Birds ◽  
Wild Birds ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
West Nile ◽  
Sylvatic Cycle ◽  
Tufted Duck ◽  
Vector Borne

West Nile Virus (WNV) is a vector-borne zoonotic disease maintained in a sylvatic cycle involving mosquito vectors and birds. To detect WNV and other flavivirus infections in wild resident and migratory birds, we tested 184 samples from 19 identified species within nine families collected during 2012–2016 from four districts in Bangladesh. We tested serum samples for the immunoglobulin G (IgG) antibody against WNV using competitive Enzyme-Linked Immunosorbent Assay (c-ELISA), whereas tracheal and cloacal swabs were subjected to consensus Polymerase Chain Reaction (c-PCR) for the detection of the flavivirus RNA. Overall, we detected 11.9% (n = 22; 95% CI: 0.07–0.16) samples were seropositive, including 15.9% in the migratory wild birds and 10.7% in the resident wild birds. The migratory wild Tufted duck showed 28.5% seropositivity, whereas the resident wild house crows showed 12.5% seropositivity. None of the swab samples was positive for flavivirus RNA infection (0%, n = 184; 95% CI: 0–0.019). These study findings recommend continued surveillance for early detection and to better understand the epidemiology of WNV and other flavivirus circulation in both birds and mosquitoes in Bangladesh.

West Nile Virus

2002 ◽  
Vol 37 (6) ◽  
pp. 676-682 ◽  
Author(s):  
Steven P. Gelone
Keyword(s):  
New York ◽  
West Nile Virus ◽  
Signs And Symptoms ◽  
Western Hemisphere ◽  
West Nile ◽  
The Public ◽  
Provider Group ◽  
Educational Effort ◽  
Control And Prevention ◽  
Vector Borne

Several infectious agents have emerged over the past two decades as a result of population migration and enhanced world travel. The introduction of arthropodborne infections to formerly unaffected geographic areas has occurred in the western hemisphere at an alarming rate. In 1999, the West Nile virus (WNV) first appeared in North America in Queens, New York and spread rapidly to infect bird and mosquito populations along the Atlantic and Gulf coasts. Significant human morbidity and mortality has been associated with the virus, with several patients deaths from encephalitis. Specific antiviral therapy is currently unavailable, but recommendations for a national plan to control and prevent the spread of this vector-borne disease have been made by the Centers for Disease Control and Prevention. Educating the public about how WNV is transmitted, how to best protect one's self, and what signs and symptoms are consistent with this infection are extremely important. Pharmacists, who have more patient interactions per unit time than any other health care provider group, are in an excellent position to play a pivotal role in this educational effort.

scholarly journals Exploring vector-borne infection ecology in multi-host communities: A case study of West Nile virus

2017 ◽  
Vol 415 ◽  
pp. 58-69 ◽  
Author(s):  
Giovanni Marini ◽  
Roberto Rosá ◽  
Andrea Pugliese ◽  
Hans Heesterbeek
Keyword(s):  
West Nile Virus ◽  
West Nile ◽  
Vector Borne

scholarly journals Host stress hormones affect host, but not vector, infectiousness for West Nile virus

2021 ◽  
Author(s):  
Lynn B. Martin ◽  
Meredith E Kernbach ◽  
Kyle Koller ◽  
Nathan D. Burkett-Cadena ◽  
Tom Unnasch
Keyword(s):  
West Nile Virus ◽  
Stress Hormones ◽  
Feeding Behaviors ◽  
West Nile ◽  
Host Interactions ◽  
Post Feeding ◽  
Southern Us ◽  
Extrinsic Incubation Period ◽  
Vector Borne ◽  
Virus Interactions

Hormones that help hosts cope with stressors also affect how hosts regulate the processes that influence their susceptibility to parasites as well as their propensity to transmit pathogens to other hosts and vectors. In birds, corticosterone (CORT), influences timing of activity, feeding behaviors, and various immune defenses that influence the number and outcomes of host interactions with vectors and parasites. No study to our knowledge, though, has investigated whether CORT variation in hosts affects the extrinsic incubation period (EIP) of a vector for a virus, one of the strongest drivers of vector-borne disease cycles. Our goal here was to discern whether CORT in zebra finches (Taeniopygia guttata) affected EIP for West Nile virus (WNV) in the mosquito, Culex quinquefasciatus, a common vector of WNV and other infections in the southern US. We experimentally manipulated CORT in birds, infected them with WNV, and then investigated whether EIP differed between vectors fed on CORT-treated or control birds. Although CORT enhanced WNV viremia in hosts, as we have observed previously, we found no effects of CORT on vector EIP or post-feeding mortality rates. These results, plus our prior observations that CORT enhances host attractiveness, indicate that some but not all stages of host-vector-virus interactions are sensitive to host stress.

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